Systems and methods for retrofitting electronic appliances to accept different content formats

ABSTRACT

Systems and methods are disclosed for using an arbitrary fixed channel to carry third-party information. In one embodiment, the present invention provides systems and methods for enabling existing content rendering devices to accept content encoded in a proprietary format, such as an encoding format used by a digital rights management system. The encoded content is rendered by the device in the normal manner, and decoded by a retrofitting appliance connected to the device&#39;s output. The retrofitting appliance may apply decoded rules and controls to the decoded content, thereby managing use of the content.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/398,325,filed Apr. 4, 2006 now U.S. Pat. No. 7,190,792, which claims the benefitof application Ser. No. 09/885,415, filed Jun. 19, 2001 (now U.S. Pat.No. 7,050,586), which further claims the benefit of U.S. ProvisionalApplication No. 60/212,642, filed Jun. 19, 2000, titled “Systems andMethods for Retrofitting Electronic Appliances to Accept DifferentContent Formats,” all of which are incorporated herein by reference.

COPYRIGHT AUTHORIZATION

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

FIELD OF THE INVENTION

The present invention relates generally to the management and use ofelectronic content. More specifically, systems and methods are disclosedfor retrofitting or adapting electronic appliances to accept contentformats different from those the appliance was originally designed toaccept.

BACKGROUND OF THE INVENTION

The rapid growth of the market for digital goods has created a need forsystems and methods to protect and enforce the rights and interests ofcontent owners. While increasing attention has been paid to thedevelopment of digital rights management (DRM) mechanisms to addressthis need, the large number of competing—and typicallyincompatible—rights management systems has created problems of its own,as existing content rendering devices are often incapable of renderingcontent encoded in accordance with the formats of the many DRM systems.

SUMMARY OF THE INVENTION

Systems and methods are disclosed for using an arbitrary fixed channelto carry third-party information. In one embodiment, the presentinvention provides systems and methods for enabling existing contentrendering devices to accept content encoded in a proprietary format,such as an encoding format used by a digital rights management system.It should be appreciated that the present invention can be implementedin numerous ways, including as a process, an apparatus, a system, adevice, a method, a computer readable medium, or as a combinationthereof. Several inventive embodiments of the present invention aredescribed below.

In one embodiment, a system for managing the use of electronic contentis described. The system includes an electronic appliance for receivingencoded content and encoded control information and for rendering theencoded content and the encoded control information through an output. Aretrofitting appliance is connected to the output, and is used to decodethe encoded content and encoded control information to recover copies ofthe original content and control information. The recovered controlinformation is then used to govern the use of the recovered content. Theretrofitting appliance uses the control information to determine whetheruse of the content is allowed, and if it is, the retrofitting appliancesends the content to an output device for presentation to a user.

In another embodiment, a method of managing electronic content isprovided. Encoded electronic content and encoded control information arereceived at a first electronic appliance. The encoded electronic contentand encoded control information form part of a data signal encoded in arendering format supported by the first electronic appliance. Theencoded electronic content and encoded control information are renderedthrough the output of the first electronic appliance, and the renderedcontent and control information are received at a second electronicappliance. The second appliance decodes the rendered electronic contentand control information to recover decoded electronic content anddecoded control information. The second electronic appliance then usesthe decoded control information to determine whether to permit thedecoded electronic content to be used in a certain manner. If the secondelectronic appliance determines that the decoded electronic content canbe used, then the second electronic appliance transmits the decodedelectronic content to an output device.

These and other features and advantages of the present invention will bepresented in more detail in the following detailed description and theaccompanying figures which illustrate by way of example the principlesof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings,wherein like reference numerals designate like structural elements, andin which:

FIG. 1 illustrates a system for practicing embodiments of the presentinvention.

FIG. 1A illustrates how a conventional system can be adapted to handlecontent encoded in a proprietary encoding format.

FIG. 2 illustrates the use of an embodiment of the present invention inconnection with Red Book CD audio content.

FIG. 3 is a more detailed illustration of the operation of a RetroBoxencoder in one embodiment of the present invention.

FIG. 4 shows an implementation of a RetroBox appliance in accordancewith an embodiment of the present invention.

FIG. 5 illustrates the operation of a RetroBox decoder in one embodimentof the present invention.

FIG. 6 provides a more detailed illustration of an implementation of aRetrobox appliance in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION

A detailed description of the invention is provided below. While theinvention is described in conjunction with several embodiments, itshould be understood that the invention is not limited to any oneembodiment. On the contrary, the scope of the invention is limited onlyby the appended claims and encompasses numerous alternatives,modifications, and equivalents. In addition, while numerous specificdetails are set forth in the following description in order to provide athorough understanding of the present invention, the present inventionmay be practiced according to the claims without some or all of thesedetails. Finally, for the purpose of clarity, certain technical materialthat is known in the art has not been described in detail in order toavoid obscuring the present invention.

The present invention provides systems and methods for enabling anexisting appliance format to carry third-party information. For example,the systems and methods of the present invention can be used to enablean audio or video compact disc (CD) player to play discs containingcontent encoded in a proprietary format, such as content stored inDigBox® or DigiFile™ containers produced by InterTrust TechnologiesCorporation of 4750 Patrick Henry Drive, Santa Clara, Calif., contentencoded in another commercial DRM format, and/or content encoded invirtually any other format. It should be understood that the presentinvention is not limited to use in connection with CD players, but mayalso be applied to any other suitable content rendering appliance,including without limitation DVD players and set-top boxes, to name justa few additional examples. Furthermore, the systems and methods of thepresent invention may be applied to devices with both analog and digitaloutputs. As used herein, an existing appliance will occasionally bereferred to as “the fixed content delivery channel.”

FIG. 1 illustrates a system for practicing embodiments of the presentinvention. Various components of the system shown in FIG. 1 will bereferred to as “RetroBox” components, since the components are operableto retrofit or otherwise adapt an existing electronic appliance to carrycontent encoded in a new format (e.g., a format that the electronicappliance was not originally designed to decode). As shown in FIG. 1, inone embodiment a generalized RetroBox system includes a RetroBox encoder102 and a RetroBox appliance 106. RetroBox encoder 102 is used bycontent creators to package content 100 and rules 101 governing thecontent's use in a format that fixed content delivery channel (e.g.,player) 104 can handle. RetroBox appliance 106 connects to the output ofthe existing format player 104, and preferably includes a decoder moduleand a core module. RetroBox appliance 106 decodes the output of existingformat player 104 to recover content 100′ and rules 101′ (or content andrules substantially similar to content 100 and rules 101, althoughslightly different due to e.g., signal degradation). The Retroboxappliance 106 can then interpret the rules, and govern the use ofcontent 100′ in accordance therewith.

Although the embodiment illustrated in FIG. 1 shows rules 101 beingpackaged with content 100, in some embodiments rules can also (oralternatively) be delivered to Retrobox appliance 106 independently ofthe content to which they relate. For example, rules could be packagedseparately and delivered to the Retrobox appliance via the fixed contentdelivery channel 104, and/or could be sent directly to the Retroboxappliance via an external connection between Retrobox appliance and,e.g., an Internet website or other remote server. Once received by theRetrobox appliance, rules can be used to govern the use of previouslyreceived content, and/or subsequently received content. Additionalinformation on the use of rules and controls to govern the distributionand use of electronic content can be found in commonly-assigned U.S.Pat. No. 5,892,900, entitled “Systems and Methods for Secure TransactionManagement and Electronic Rights Protection,” issued Apr. 6, 1999 (“the'900 patent”), which is hereby incorporated by reference in itsentirety. The terms “rules”, “controls”, and “control information” areused interchangeably in the following discussion.

As shown in FIG. 1, content 100 and rules 101 arrive at encoder 102.Encoder 102 packages them and puts them into a format that fixed contentchannel 104 can interpret. The RetroBox appliance's decoder retrievesthe encoded content and rules from the output of the delivery channel,and performs the necessary information recovery steps required toextract the content and rules.

FIG. 1A illustrates how an existing system 110 can be adapted to handlecontent encoded in a proprietary format using the techniques describedabove. Referring to FIG. 1A, system 110 includes an electronic appliance104 connected to an output device 109. In the example shown in FIG. 4,electronic appliance might comprise a television set-top box, a digitalversatile disk (DVD) player, a videocassette player, or the like, andoutput device 109 comprises a television set or other video displaymonitor. It will be appreciated, however, that the concepts described inconnection with FIG. 1A are readily applicable to a wide variety ofother electronic appliances and output devices (e.g., CD players andspeakers).

Electronic appliances 104 are typically designed to accept a certaintype (or types) of encoded electronic content 113 (e.g., a DVD, CD,videocassette, satellite signal, cable signal, or the like). Electronicappliance 104 decodes or transforms content 113 into a form that theoutput device can handle, and sends it to the output device forpresentation to a system user. As shown in FIG. 1A, the presentinvention provides a way to adapt system 110 to handle content 114 thatis encoded in a proprietary format, such as a proprietary digital rightsmanagement format. In particular, in system 110′ electronic appliance104 is retrofitted with Retrobox application 106. Retrobox application106 connects to the output of electronic appliance 104, and is operableto intercept signals from electronic appliance 104 to output device 109.Retrobox 106 processes these signals and produces new or modifiedsignals which it sends to output device 109 for presentation to a systemuser.

FIG. 2 illustrates the use of the RetroBox system in connection with RedBook CD audio content. As shown in FIG. 2, encoder 202 outputs data thatis in Red Book CD audio format 203. For example, data 203 may be storedon a CD. CD player 204 plays the CD as it would any other audio CD, butif one were to listen to the output 205 of the player, it would soundlike noise.

However, RetroBox appliance 206 picks up the analog signal 205 emanatingfrom the line-out port of CD player 204. RetroBox appliance 206 performsanalog-to-digital (A/D) conversion and resampling to obtain a digitalsignal, and proceeds to demodulate and decode the resulting digitalsignal in a sequence of steps that will be described in more detailbelow. At the end of this process, the content (or a substantiallysimilar version of the content) 200′ and rules 201 that entered theencoder 202 will reappear.

It will be appreciated that if the CD player in question has a digitaloutput port, then the A/D and resampling steps could be dispensed with,and the digital stream could be decoded accordingly. Alternatively, orin addition, Retrobox appliance 206 could be designed to process theanalog output directly. For example, Retrobox appliance could bedesigned to perform what would effectively be an analog-to-analogconversion by extracting rules directly from the analog output anddescrambling the analog content in accordance therewith to recover theoriginal audio content 200′.

A key idea is to treat the fixed content delivery channel (FCDC) as acommunications channel under the classical Shannon communications model.Essentially, the channel transports the information yet introducesdistorting noise. As with any communications channel, this one has acapacity. Capacity is a function of the distorting noise and gates themaximum amount of information (bits/second) that may flow through it.This capacity may be achieved through a variety of techniques such aserror-control and modulation coding combined with data compression andencryption (for security.)

In the aforementioned example of an audio CD player, the process of redbook decoding is information lossless, yet the process of D/A conversionis not. This is the principal source of distortion. In the case of videoCD (MPEG-1 based) or any lossy coder (MPEG-2 based), additional noisewill typically be introduced by the decompression process. A way toguard against this is to apply more aggressive error control codes tothe content. Ultimately,.the greater the noise on the channel, the lessthe capacity will be. However, compressing the data in advance willboost the amount of information each symbol going through the channel iscarrying. Another technique would be to maintain the content in analogform, and to transmit control (and rules) information through theRetroBox channel.

FIG. 3 is a more detailed illustration of the operation of the RetroBoxencoder in one embodiment of the present invention. The encoder takesrules and content and packages them (302, 306). In some embodiments, therules and content may be compressed (308) to minimize the data'sfootprint. In some embodiments, the data may also be encrypted (310).Error control coding can be applied (312) to protect the content fromchannel distortion. The data are then formatted (314) to pass throughthe channel. In the case of CD audio, for example, this might mean thatthe data is encoded into Red Book CD format. In the case of an analogcable set top box, the formatting process would typically entaildigital-to-analog conversion and modulation onto the channel carrier. Inshort, the formatting process makes use of standard encoding techniquesto transform data into the format of the content delivery channel.

As indicated above, in some embodiments it may be desirable to applyencryption, compression, and/or error correction transformations to thesignal before it is converted into the format of the content deliverychannel. It will be appreciated that any suitable encryption,compression, and/or error correction algorithms could be used forpurposes of practicing the present invention, and, in some embodiments,no encryption, compression, and/or error correction need be used.Examples of well-known error-correction techniques include withoutlimitation such techniques as repetition, Hamming or other linear blockcodes, cyclic codes, quadratic residue codes, Golay codes, Reed-Muellercodes, Reed-Solomon codes, convolutional codes, trellis codes, and thelike. A basic idea of such techniques is that by including redundancy ina communication stream, the corruption or loss of some of theinformation in the stream can be corrected or detected. Examples ofwell-known encryption/decryption algorithms are described in Menezes etal., Handbook of Applied Cryptography at pages 145, and 133-312 (CRCPress 1996), which is hereby incorporated by reference.

FIG. 4 shows an implementation of the RetroBox appliance in accordancewith an embodiment of the present invention. As shown in FIG. 4,RetroBox appliance 401 preferably includes a decoder 402 and anappliance core 404. As discussed above, decoder 402 extracts content andrules 403 from the FCDC output stream 400. Appliance core 404 performsinterpretation and application of rules to content, and transacts withthe user. For example, in one embodiment appliance core 404 comprises aninstance of the InterRights Point™ software or Rights/System™ softwareproduced by InterTrust, or an implementation of the Rights OperatingSystem software/hardware described in the '900 patent. One of ordinaryskill in the art will recognize, however, that other software orhardware could be used instead, depending on the rights managementsystem that is used to encode the content and rules. Note that appliancecore 404 may have to re-encode the content into a format that can bedisplayed by the consumer's output device. This can be done usingstandard techniques, such as those used by the content delivery channelitself.

The dashed lines in the FIG. 4 illustrate (optional) lines of control.These may not be present in all devices due to constraints on the FCDC.For instance, a common audio or video CD player typically cannot becontrolled from the outside (except for physically pushing buttons onthe front panel). This may limit the number of business models that canbe implemented on these platforms.

FIG. 5 illustrates the operation of the RetroBox decoder in oneembodiment of the present invention. In unformat step 504, encodedcontent 502 is translated from the FCDC output format into one that thedecoder can interpret. In the case where the FCDC output format isanalog, this step involves sampling and A/D conversion. Techniques forperforming sampling and A/D conversion are well-known in the art, andany suitable technique can be used. Step 506 involves applyingerror-correction decoding to return the data to its input state,preferably verbatim, and will be performed if error correction wasapplied by the Retrobox encoder to the original signal (as shown in FIG.3). The information may (if applicable) be subsequently decrypted (508)and decompressed (510) prior to the unpacking (512) of rules andcontent. The rules are then used to govern the use of the content by thesoftware and/or hardware in the appliance core, as described, forexample, in the '900 patent. If the appliance core determines thatpermission has been granted to use the content, the content can betransmitted to an output device for presentation to a user.

FIG. 6 provides a more detailed illustration of a Retrobox appliance 600in accordance with an embodiment of the present invention. Retroboxappliance 600 may comprise a general-purpose electronic appliance suchas a personal computer, or a specialized electronic device such as aself-contained portable unit (or card) that can be attached to (orintegrated with) the fixed content delivery channel (e.g., by pluggingit into the FCDC's line-out port). Retrobox appliance 600 will typicallyinclude a processor 602, memory 604, a buffer 618 for storing incomingcontent from the FCDC, an analog-to-digital and digital-to-analog signalprocessor 619, and a bus 612 for connecting the aforementioned elements.As shown in FIG. 6, in some embodiments Retrobox appliance 600 may alsoinclude an optional network interface 610 for sending and receivingrules, permissions, content, audit information, and/or the like over anetwork 620 such as the Internet. In some embodiments, Retroboxappliance 600 also (or alternatively) includes a secure processing unit603 such as that described in the '900 patent. A secure processing unit603 can help enhance the security of sensitive operations such as keymanagement, signature verification, and other aspects of the rightsmanagement process.

The operation of Retrobox appliance 600 will typically be controlled byprocessor 602 (and/or SPU 603) operating under the guidance of programsstored in memory 604. Memory 604 will generally include both high-speedrandom-access memory (RAM) and non-volatile memory such as a magneticdisk and/or flash EEPROM. As shown in FIG. 6, memory 604 may include avariety of programs or modules for controlling the operation of Retroboxappliance 600. For example, memory 604 will typically include one ormore content rendering applications 630 for presenting electroniccontent to an output device of the fixed content delivery channel (e.g.,a television set, monitor, speakers, etc.). Rendering applications 630may, for example, work in connection with digital-to-analog converter619 to convert digital content to analog form. Memory also includes arights management program 629 such as that described in the '900 patentfor applying policies, rules, and/or controls to govern the use ofcontent or the performance of events.

One of ordinary skill in the art will appreciate that the systems andmethods of the present invention can be practiced with electronicappliances that are similar or identical to that illustrated in FIG. 6,or with electronic appliances that do not possess some of the componentsshown in FIG. 6 and/or that possess other components that are not shown.Thus it should be appreciated that FIG. 6 is provided for purposes ofillustration and not limitation as to the scope of the invention.

Although the foregoing invention has been described in some detail forpurposes of clarity, it will be apparent that certain changes andmodifications may be practiced within the scope of the appended claims.For example, although several embodiments have been described in thecontext of CD players, it should be understood that the RetroBox conceptis much broader. For example, without limitation, the channel may be aset-top box, a TV atmospheric channel, or any other suitablecommunications medium. Furthermore, while an embodiment was presentedthat included an appliance core on the appliance side, in otherembodiments the RetroBox could be used to transport secret informationthat could only be played by people with the appropriate extension to astandard player. Further, the content could be combined with data hidingsuch that, in the case of CD audio, the disc would play music undernormal circumstances. It should thus be noted that there are manyalternative ways of implementing both the processes and apparatuses ofthe present invention. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

1. A method of packaging electronic content and control information foruse by a system including a retrofitting appliance, the methodcomprising the steps of: encrypting the electronic content and thecontrol information; transforming the encrypted electronic content andcontrol information into a format that can be rendered by an electronicappliance; storing the transformed, encrypted electronic content andcontrol information on a computer readable medium for provision to anelectronic appliance operable to render the transformed, encryptedelectronic content and control information and output the encryptedelectronic content and control information to an input of theretrofitting appliance, the retrofitting appliance being operable todecrypt the encrypted electronic content and control information, tomake a determination based on the control information as to whether topermit use of the electronic content, and to selectively transmit theelectronic content to an output device based on the results of thedetermination.
 2. The method of claim 1, further comprising the step of:compressing the electronic content and the control information.
 3. Themethod of claim 1, further comprising the step of: applyingerror-correction coding to the encrypted electronic content and controlinformation.
 4. A non-transitory computer readable medium storinginstructions that, when executed by a computer, cause the computer toperform steps comprising: packaging electronic content and the controlinformation; transforming the packaged electronic content and controlinformation into a format that can be rendered by an electronicappliance; and storing the transformed, packaged electronic content andcontrol information on a computer readable medium for provision to anelectronic appliance operable to render the transformed, packagedelectronic content and control information and output the packagedelectronic content and control information to an input of a retrofittingappliance, the retrofitting appliance being operable to unpackage thepackaged electronic content and control information, to make adetermination based on the control information as to whether to permituse of the electronic content, and to selectively transmit theelectronic content to an output device based on the results of thedetermination.
 5. The computer readable medium of claim 4, furthercomprising instructions that, when executed by a computer, cause thecomputer to perform steps comprising: encrypting the packaged electroniccontent and control information.
 6. The computer readable medium ofclaim 4, further comprising instructions that, when executed by acomputer, cause the computer to perform the step of: compressing thepackaged electronic content and control information.
 7. The computerreadable medium of claim 6, further comprising instructions that, whenexecuted by a computer, cause the computer to perform the step of:applying error correction coding to the compressed, packaged electroniccontent and control information.
 8. An apparatus comprising: a storagedevice including stored instructions; and a processor for executing thestored instructions, the stored instructions including instructionsthat, when executed by the processor, cause the apparatus to performsteps comprising: packaging electronic content and the controlinformation, transforming the packaged electronic content and controlinformation into a format that can be rendered by an electronicappliance, and storing the transformed, packaged electronic content andcontrol information on a computer readable medium for provision to anelectronic appliance operable to render the transformed, packagedelectronic content and control information and output the packagedelectronic content and control information to an input of a retrofittingappliance, the retrofitting appliance being operable to unpackage thepackaged electronic content and control information, to make adetermination based on the control information as to whether to permituse of the electronic content, and to selectively transmit theelectronic content to an output device based on the results of thedetermination.
 9. The apparatus of claim 8, in which the storedinstructions further include instructions that, when executed by theprocessor, cause the apparatus to perform the steps of: encrypting thepackaged electronic content and the control information.
 10. Theapparatus of claim 9, in which the stored instructions further includeinstructions that, when executed by the processor, cause the apparatusto perform the step of: compressing the encrypted, packaged electroniccontent and control information.
 11. The apparatus of claim 10, in whichthe stored instructions further include instructions that, when executedby the processor, cause the apparatus to perform the step of: applyingerror correction coding to the compressed, encrypted, packagedelectronic content and control information.
 12. A method comprising:providing encoded electronic content and encoded control information toan electronic appliance operable to render the encoded electroniccontent and encoded control information and output the encodedelectronic content and encoded control information to an input of aretrofitting appliance, the retrofitting appliance being operable todecode the encoded electronic content and encoded control information,to determine whether to permit the use of the decoded electronic contentbased on the decoded control information, and to transmit the decodedelectronic content to an output device based on the determination. 13.The method of claim 12, further comprising packaging the encodedelectronic content and encoded control information into a data signal.14. The method of claim 13, further comprising: encrypting theelectronic content and the control information; encoding the encryptedelectronic content and control information in a rendering formatsupported by the electronic appliance.
 15. The method of claim 13,further comprising compressing the electronic content and controlinformation.
 16. The method of claim 13, further comprising applyingerror correction coding to the data signal.